With blooms that last throughout summer, crape myrtles (Lagerstroemia indica) are an attractive addition to the home garden. Also known as the lilac of the south, this small- to medium-sized tree is identifiable by its smooth trunk, constant summer blooms and fall foliage. Blooms are available in shades of white, purple, pink and red. From dwarf sizes that fit in containers to full-size trees up to 30 or 40 feet tall, select the right crape myrtle for the space desired within U.S. Department of Agriculture plant hardiness zones 6 to 10.
Selecting the Right Tree
Consider the location of the tree before selecting a variety. For containers and small spaces, look for miniature varieties like the World's Fair crape myrtle (Lagerstroemia indica, 'World's Fair'), which only reaches a height of 2 feet and offers fuchsia-red blooms. For flower beds close to the house, select a dwarf crape myrtle, like the Victor crape myrtle (Lagerstroemia indica, 'Victor') which reaches 6 feet tall and offers bright, deep red blooms.
For wide open spaces, standard crape myrtle trees offer beauty and shade. Sarah's Favorite crape myrtle (Lagerstroemia indica, 'Sarah's Favorite') makes a wonderful shade tree as it grows up to 25 feet tall with white blooms.
Choosing a Location
Plant crape myrtles in full sun to get the best blooms. While they can tolerate some shade, they will not bloom as vigorously. Crape myrtles should be planted at least half the width of the mature tree away from the home or other structures. For example, if the maximum mature width of the tree is 15 feet, plant it no closer than 7 1/2 feet away from the nearest structure. This spacing will vary depending on the variety.
In USDA zone 6, crape myrtles may die back to the ground every winter, but planting crape myrtles in an area where they are protected from the harshest cold weather may keep the trunk above-ground alive. Select a sheltered location where the plant is blocked from cold north winds, usually the south-side of a house, which also offers the benefit of the warm sun. In areas where the tree cannot be protected, opt for smaller dwarf varieties and grow them as perennials that return from the roots each year.
Planting a Crape Myrtle
Within any of its recommended USDA zones, late fall to early spring is the ideal time to plant a crape myrtle, while the plant is still dormant; however, it is possible to plant a crape myrtle in the summer while it is blooming to ensure the color works for the space.
Water the root ball thoroughly before planting. Dig a hole three times as wide as the root ball and just deep enough that the top of the root ball is even with the surface of the soil when placed in the hole.
Crape myrtles like slightly acidic soil at 6.0 to 6.5 pH. Use an at-home soil test to determine soil acidity. To lower soil pH by 1 point, add 6 ounces of elemental sulfur per 25 square feet of soil, or each 5-foot by 5-foot prepared space, and work it into the top few inches of soil with a rake.
Holding the tree by the root ball, carefully place the tree in the hole. Never carry the tree by the trunk because this can damage the roots where they meet the tree. If the root ball is covered by burlap, carefully cut this off and remove all twine and wires that wrap around the root ball or the trunk of the tree. Ensure the tree is straight, and backfill the hole with soil. Fertilizer is not required when planting crape myrtles.
Water thoroughly after planting and any time the soil is dry 1 inch below the surface.